b75326c201
RFC4862 5.5.3 e) prevents received Router Advertisements from reducing the Valid Lifetime of configured addresses to less than two hours, thus preventing hosts from reacting to the information provided by a router that has positive knowledge that a prefix has become invalid. This patch makes hosts honor all Valid Lifetime values, as per draft-gont-6man-slaac-renum-06, Section 4.2. This is meant to help mitigate the problem discussed in draft-ietf-v6ops-slaac-renum. Note: Attacks aiming at disabling an advertised prefix via a Valid Lifetime of 0 are not really more harmful than other attacks that can be performed via forged RA messages, such as those aiming at completely disabling a next-hop router via an RA that advertises a Router Lifetime of 0, or performing a Denial of Service (DoS) attack by advertising illegitimate prefixes via forged PIOs. In scenarios where RA-based attacks are of concern, proper mitigations such as RA-Guard [RFC6105] [RFC7113] should be implemented. Signed-off-by: Fernando Gont <fgont@si6networks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.